A prayer service for standardized tests has drawn criticism for one Baltimore school principal.

Jael Yon held the event for two years for Northeast Baltimore's Tench Tilghman elementary and middle school students. A flier distributed to some 400 students and their parents described the event as a way to "come together, as one, in prayer and ask God to bless our school to pass the test."

The 30-minute prayer service was strictly voluntary and was held on a Saturday along with a review of course work to prepare for assessment tests. Parents of students attending the school made the request of Yon, who's in her second year as principal, to hold both the prayer service and the review.

The Baltimore Sun reported that school officials are investigating the event.

"While we, as a district, understand that prayer plays an important role for many in our school communities, it is not appropriate for public institutions of education to promote any particular religious practice," the school system said in a prepared statement.

Jimmy Gittings, president of the city principals' union, told the newspaper he supported Yon, "an exceptional principal trying to do what's best for our children in the Baltimore City school system."

Gittings added, "The only individuals I hold accountable for these injustices for Ms. Yon are the narrow-minded politicians from some 50 years ago, for removing prayer from our schools. Once prayer was removed from our schools, the respect for our teachers and administrators has been increasingly out of control."

Many parents have also spoken out in support of Yon.

LaTonya Greene, a parent volunteer at the school and mother of four students, said, "A lot of our kids have a lot of problems, and sometimes the school is their safe haven. I see what they go through every day, and sometimes you need to just pray about it."